WINTER OUTLOOK: LA NADA PREDICTING WEATHER IS UP IN THE AIR.

Byline: Eric Leach Staff Writer

With summer ending Thursday, weather experts don't see El Nino or La Nina on the horizon - just a big ``La Nada,'' a neutral condition that makes it especially difficult to forecast winter weather.

Frigid ocean waters have accompanied La Nada this year, leading to cooler onshore temperatures - five degrees below normal already in September. This could lead to a colder and drier winter.

Weathermen are even more hesitant than usual to forecast winter conditions without the stabilizing effect of either an El Nino or a La Nina.

``Those conditions give you some guidance in long-term forecasts,'' said Bill Patzert, a climatologist with the Jet Propulsion Laboratory in Pasadena. ``When you have neutral conditions, that's La Nada. La Nada makes the forecast tough.''

El Nino conditions occur when tropical ocean temperatures warm, typically sending wetter weather toward Southern California. The La Nina effect, the opposite, brings cooler ocean temperatures and drier weather.

``It's like with teenagers: Without the structure, you can have bad behavior. Last winter was one of the rainiest winters on record,'' Patzert said, noting that, while some say there were weak El Nino conditions present, the savage Southern California storms swept down from the Gulf of Alaska, surprising everyone.

Larry Riddle, climatologist at the Scripps Institute of Oceanography at the University of California, San Diego, said cooler conditions in August and September indicate a cool, dry winter.

``But it doesn't always happen that way,'' Riddle said. ``The weather does not pay attention to what we tell it.''

Still, Patzert feels fairly safe predicting cooler, drier conditions this winter, in part because he sees a slight tendency toward La Nina-like conditions.

Whether this winter is cooler than last year, Southern Californians will pay more to heat their homes following steep hikes in natural gas. Based on current projections, a typical residential customer in the Los Angeles area who paid $83 a month last year could see the gas bill rise to $110 this winter, according to Peter Hidalgo, a spokesman for the Southern California Gas Company.

``The Gas Company has been reaching out to its customers to be prepared for higher natural gas prices,'' he said. ``When Mother Nature turns down the temperature, customers tend to turn up their furnaces. Energy prices are increasing at the wholesale level, and, in the winter months, the average customer uses their gas appliances more.''

Temperatures in downtown Los Angeles were 2.9 degrees below normal in June, 1.2 below normal in July, 2.1 below normal in August and 5.5 below normal so far in September.

The result is improved air quality and a fire danger, despite the heavy growth of vegetation because of last winter's rainfall.

Inspector John Mancha, a spokesman for the Los Angeles County Fire Department, said the area still faces a potentially explosive fire season if hot, dry Santa Ana winds hit the area.

``As of right now we are enjoying this little change of weather, which has slowed fires,'' he said. ``But the recent weather doesn't change our status because our fire season is generally October or November. When the Santa Ana winds come in, it will dry things out and put us right back in the danger area. We're not out of the woods yet.''

Eric Leach, [phone]

eric.leach(at)dailynews.com

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CHILLY END TO SUMMER

SOURCE: National Weather Service